1. Field of the Invention
The present invention relates to an ink-jet printer which records an image on a recording medium by discharging an ink from nozzles.
2. Description of the Related Art
As an ink-jet printer which records an image on a recording medium by discharging an ink or inks from nozzles, Japanese Patent Application Laid-open No. 2008-251303 describes an ink-jet printer which discharges an ink or inks from a plurality of nozzles formed on an ink-jet head which is reciprocatively movable in a main scanning direction together with a carriage and which records an image on a recording medium transported in parallel to a sub scanning direction (secondary scanning direction). In the case of the ink-jet printer described in Japanese Patent Application Laid-open No. 2008-254303, the plurality of nozzles are aligned in the sub scanning direction. In a case that the positional accuracy of the nozzles is unsatisfactory and the alignment direction of the nozzles is inclined with respect to the sub scanning direction, the ink is discharged from the nozzles in the first scanning at the same discharge timing as that provided when the alignment direction of the nozzles is parallel to the sub scanning direction. In the second scanning and the followings, the discharge timing of the ink to be discharged from the nozzles is advanced or delayed depending on the inclination of the alignment direction of the nozzles so that the landing position of the ink is deviated thereby in the main scanning direction.
In this procedure, if the landing position of the ink are not deviated, then the ink, which is discharged from the nozzle positioned at the end on the upstream side in the transport direction in certain scanning, has the landing position which is deviated in the main scanning direction from the landing position of the ink which is discharged from the nozzle positioned at the end on the downstream side in the transport direction in the next scanning, and the image quality of the image to be recorded is deteriorated. In view of the above, in the ink-jet printer described in Japanese Patent Application Laid-open No. 2008-254303, the deviation of the ink landing position is eliminated by deviating the ink landing position in the main scanning direction as described above. Accordingly, the image quality of the image to be recorded is improved.
In this context, in the ink-jet printer described in Japanese Patent Application Laid-open No. 2008-254303, the amount of deviation of the ink landing position is more increased in the scanning to be performed later in relation to the second scanning and the followings. Therefore, the portion, which is recorded in the first scanning, is recorded at a substantially central portion of the recording medium in relation to the main scanning direction. The portions, which are recorded by the scanning performed later, are recorded at positions deviated toward one side from the central portion of the recording medium with respect to the main scanning direction. A large difference appears in the lengths in relation to the main scanning direction of the blank spaces or margins disposed on the both sides in relation to the main scanning direction of the image recorded on the recording medium.